3D Printing – Full Service FAQ

Rapid-prototyping can be intimidating for someone new to the process, but have no worries! Here at the UM3D Lab, we’ve answered the questions we get most often about rapid prototyping (3D printing) to create a handy list of Frequently Asked Questions.

Frequently Asked Questions

Most of our printers are FDM (fused deposition modeling), which means they extrude melted plastic filament and lay down layers of it to create a 3D object, much like building a stack of pancakes or a layer cake. They also create a support structure to make sure your part is as close to your design as possible. This support structure is later dissolved or melted away.

All the 3D lab needs to print is a stereolithography file with the extension .stl. Most CAD modeling softwares (Rhino, Solidworks, Maya, 3D Studio Max, etc.) can export a CAD model as a STL. (Simply save as, or export to an STL file, depending on your software.)

An STL file separates 3D models into printable layers. Your STL file is the key thing we need to print– from there we put it through the fixing and setup software the printer needs for it to be successfully built. The software(s) needed to create an STL file are available to use in the Digital Media Commons- the UM3D Lab computer lab and Groundworks.

1. Across the hall from the UM3D Lab is Groundworks, another affiliate of the library and the Digital Media Commons. In Groundworks they have software like Rhino and Solidworks which can be used to create 3D models for printing. If you don’t know how to use the software, no worries: they have a patient, knowledgeable staff, and Lynda.com accounts with step-by-step tutorials on how to create the model you’ve been dreaming of.

2. Some websites offer free files ready for 3D Printing. If you’re looking for printable jewelry, figurines, household goods, and other cool stuff, check out the selection at Thingiverse.com.

3. If you have an object you’d like to replicate, the UM3D Lab has a 3D scanner! It can scan objects of nearly any size (with details larger than 0.2mm) and create an STL file ready for printing. (Price begins at $15 dollars per hour.) This service has been used to scan medical equipment, motorcycle frames, hundred-year-old sculptures, architectural models, rocks, dinosaur footprints, and people’s bodies. If you bring it to us, chances are we can scan it.

Deciding which printer to use depends on the final outcome of your part. If you need something with large overhangs, or that needs to be very durable, printing out of plastic is the best choice. Mechanical parts, parts with threads, interlocking parts all print best out of plastic. The print area for the Dimension printer is 8” x 8”. It’s resolution per layer is 0.254 mm (0.010 in.).

If you need something with smaller details or just a smaller piece, the ProJet can provide the best finished part. The resolution per layer is 0.016 mm (0.0006 in.). Also the material used is a bio compatible plastic, which is handy for medical applications. It also works well for investment casting.

For lower-quality, but faster iterations, consider using the Cube 3D printer through the 3D Lab’s Open-Services 3D Printing.

First, look at your CAD model and look at its edges– does it look “closed”? Are the edges showing the ‘interior’ of the object? (Imagine a smashed cardboard box where the edges don’t meet up.) If so, this will be a problem for printing: re-work your part to have closed edges, or consult your program’s help menu. Some programs like Rhino allow you to see if your part is closed, or watertight– if it is, chances are it will print! (For more information on how to fix or alter parts, check out the UM3D Lab’s video tutorials on how to fix parts in Magics, available on computers in the Vislab in the digital Media commons– Room 1401)

The UM3D Lab staff checks all submitted parts for errors before we send them to print. While we are happy to correct small flaws– often as a result as the software and not the user– we cannot fix parts with large structural problems. Fixing a part with major errors often drastically changes the part, and we don’t want to alter someone’s vision for their part by filling in large holes or assuming it should look a certain way.

Even if your part has no obvious holes or bad edges and looks good to print, it still may have issues for the 3D printers. Sometimes the surfaces of objects may overlap, even in very tiny places– this confuses the printer and can result in bad prints or damage to the printers. These tiny overlaps are fixed by the UM3D Lab staff using Magics, a special software designed to prepare 3D models for rapid-prototyping.

No. If you have a specific request or concern, you can email um3d-rp@umich.edu to meet with a consultant or Shawn O’Grady, the Rapid Prototyping Specialist (ogradys@umich.edu). The UM3D Lab is always open to walk-ins who have questions or are curious as to our services!

Yes! We have examples of a wide range of parts printed in the materials we offer. If you are unsure as to the qualities of the materials, stop in to see and feel the sample prints. Also, feel free to check out the design guides to see how each printer will handle certain features.

The UM3D Lab uses an online uploading system for processing client models. (Please do not e-mail us your files! E-mail is great for questions, but e-mailed files are easily lost or buried.) When you use our online form to upload your parts, your part is automatically added to a dropbox where our RP specialists and consults can see and process them. When you are ready to submit, double check that you have saved your part as an STL file or as a zip file. Next, click the button below to access our submission form!

Yes, of course! However, if they are all a part of the same job, please submit them all at one time instead of uploading each file individually. To do this, put all your files in a folder and compress them into a .zip file.

One of the 3D Lab’s talented RP consultants, or Shawn O’Grady, the RP specialist, will look at your part and fix any small issues with your model. If there is an issue with a model, Shawn or a consultant will contact you about the problem.

If the parts look good to print, you will receive an e-mail. This e-mail will verify what and how many parts you are printing, out of what material, and how much it will cost. You will be asked if you want to proceed with the print. The UM3D Lab will never print a part without direct approval and direction to do so from our clients.

When you reply to the email and approve your part to be printed, we create an invoice with a quote and estimated finish time. We make this estimate based on the complexity of the part, how long with print will take and how many parts are in the print queue. Typically, most parts are finished within 3-5 days after being approved to print.

However, during busy times of the year (towards the end of each semester) lots of people want to print, and the print queue becomes long. Because parts are processed in the order they are received, a rush in parts to be printed can result in a push back of production times. For this reason, prior planning is important, especially if you have a deadline you will need your part by.

Depending on the size and complexity of the part, the build time can range– from a few hours to a few days. (While rapid prototyping is rapid, it is not instant.) The printers run during the day, as well as overnight and on weekends– we are excited about rapid prototyping and want to get you your part ASAP! Remember: parts with support material also need to soak in a tank to remove the material– which can take as a long as a day depending on the amount of support material that needs to dissolve.

Anyone can use the UM3D Lab printers. Because we are an affiliate of the University of Michigan Library system, students, faculty and staff take precedence over other clients.

Outside clients (not related to the university) can use the 3D Lab’s rapid prototyping services at double the cost of campus clients. This rule is in place to protect our local small businesses. If you are not a student or staff member, it is in your best interest to check out some of the other 3D printing services available in Ann Arbor.

That depends on each material. ABS plastic can be sanded, painted, and drilled, but we recommend building holes into your part before printing rather than trying to drill them later; putting drilling pressure on the part can lead to rough edges, breaks, or non-precisely drilled holes. Plastic prints vary in the amount of material inside the prints: they can be printed sparse-density, high-density, and solid.

Similarly, ProJet parts can also be sanded, painted, and drilled but be sure to use a mask since the parts can release a acrylic dust that is harmful when inhaled.

When you come to pick up your finished part, you can pay by credit card, or, if the project is funded through a University of Michigan department, it can be paid by a shortcode. Most clients choose to pay by credit card. We do not accept cash.

If you are paying by shortcode, you must have your shortcode written on your invoice and signed by the finance office of your department. E-mail um3d-rp@umich.edu for questions regarding shortcode payment.

Yes. If the size of your part exceeds the size of the printable area, the 3D lab RP consultants can, (with your permission) digitally cut your piece in two (pre-printing) with a jigsaw cut. This allows parts to be printed in many pieces and fit together post-printing. Typically, a mixture of glue and ABS plastic is used to secure these two parts together. Many clients choose this option because it allows them to have their prototype printed at accurate size.

As a general rule, if two parts need to fit inside of each other, there must be at least 0.2mm between surfaces. A 0.2 mm clearance will provide a tight fit– depending on the part, it still may need some sanding to fit. For a looser fit, create a tolerance greater than 0.2 mm.

The 3D lab will never print your part without direct authorization from you. If you haven’t approved your part to print– no worries! Just upload a new version with updates in the instructions. If you submitted your part and you decide you no longer need the print, just send an email to um3d-rp@umich.edu to let us know.

If you have already approved the print, contact Shawn O’Grady at ogradys@umich.edu. We understand that last-minute iterative changes sometimes happen. The UM3D lab runs on a cost-recovery system, so if your part is printing, or has already printed, you will only be charged for the material used. If you then submit additional parts to be printed, you will only be charged one set-up fee for the job.

The UM3D lab has Cube 3D printers (version 2.0!) available for student, faculty and staff use. The good news: you don’t have to pay to use it! As a self-service machine, you do not need to submit parts to the lab or pay for a set up fee, but this also means you need to educate yourself on how to use the machine, buy a cartridge of material, and schedule time for your prints. (Don’t worry, it’s easy to do.)

To get started with Open-Access 3D printing, visit the UM3DLab website and click the Walk-up 3D printing button on the home page. Below are step-by step instructions, including a link to the Cube how-to videos, an informative (and even a little funny) series of videos that cover everything you need to know about using the Cube 3D printer.

After you’ve watched the videos and feel familiar with the printer, take the knowledge test. After you’ve taken the test, a consultant will e-mail you back to let you know if you have passed. If you have, you will be added to the Event Management System (EMS), and can begin scheduling a time to use the Cube! Remember– you need to order your own materials, which can be done online through Cubify or Staples. Please note: ABS plastic clogs the Cube Printers: for this reason, only PLA plastic is allowed when using Open-Source 3D Printing.

From there you can begin using the Cube 3D printers. Remember to clean up your area and return your key when you are finished.

We strive to help people innovate and create — we thrive on curiosity and new ideas. Send us an e-mail (um3d-rp@umich.edu), call us (+1 734-615-9699), or simply stop in and say hello– you are always welcome here! Visit us in the Digital Media Commons on the first floor of the Duderstadt, on the North Campus of the University of Michigan between 9am and 6pm.